Electric-arc lamp.



No. 674,061 Patented May l4,-l90l.

w. H. NORTHA-LL.

ELECTRIC ARC LAMP.

(Application filed Jan. 18, 19(90.) (No Model.) 2 Shuts-Sheet l.

W. H. NORTHALL.

ELECTRIC ARCVLAMP,

(Applicltion filed Jan. 18, 1900.; (No Model.) 7 2 Sheets-Sheet 2.

No. 674,067. Patented May I4, l90l.

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UNITED STATES PATENT OFFICE.

WILLIAM H. NORTHALL, OF ELWOOD, INDIANA, ASSIGNOR TO THE LEA MANUFACTURING COMPANY, OF SAME PLACE.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent N 0. 674,067, dated May 14,1901. Application filed January 18, 1900. Serial No. 1,909. (No model.)

To all whom it may concern:

Be it known that LWILLIAM H. NORTHALL, a citizen of the United States, residing at Elwood, in the county of Madison and State of Indiana, have invented certain new and use ful Improvements in Electric-Arc Lamps, of which the following is a specification.

My inventionrelates to that variety of electric-arc lamps'wherein the arc is formed within a substantially air-tight inclosure; and it consists in various details of construction and arrangements of parts whereby a simple, inexpensive, and highly-efficient lamp of said variety is produced.

A lamp embodying my said invention will first be fully described and the novel features thereof then pointed out in the claims.

Referring to the accompanying drawings,- Which are made a part hereof, and on which similar reference characters indicate similar parts, Figure 1 is a side elevation of a lamp of the character in question embodying my improvements; Fig. 2, an elevation of the interior thereof, the casing or globes being cut away or cut in half, as seen from the point indicated by the dotted line2 2 in Fig. 1; Fig. 3, a horizontal sectional view as seen from the dotted line 3 3 in Fig. 2, showing the interior of the lamp below the resistance-coils in top plan; Fig. 4, a central sectional view of the principal portions 'of the lamp, on a somewhat-enlarged scale, as seen from the dotted line at 1 in Fig. 1; Fig. 5, a horizontal sectional view as seen from thedotted line 5 5 in Fig. 4; Fig. 6, a detail sectional view on the dotted line 6 6 in Fig. 4.; Fig. 7, a detail elevation as seen from the dotted line 7 7 alongside Fig. 4:, showing the catch by which the inclosing casing is secured together; Fig. 8, a detail view of an alternative construction of one of the catches for clamping and holding the inside globe, and Fig. 9 a detail sectional view of the upper-carbon holder.

I will first describe the frame of my improved lamp, the main portion of which is a tubular casting 1, within and upon which the other portions of the lamp are secured. Upon the upper end of this casting is placed a cap 2, which is there rigidly and strongly secured in place. Hinged to this cap and to a suitable projection on the tubular casting 1 are the casing halves or sides 3 and 4. These are carried by hinged pivots p p and when closed This forms an extremely simple and expedi tious means whereby the globes to the lamp may be removed for cleaning, renewal, or replacement. The whole structure is carried from any suitable support from which a connecting wire or cord may be run to and pass through the loop structure 6, formed on or connected to the cap 2. This structure, as best shown in Fig. 1, is preferably composed of two ears with a sheave or roller secured between them; but obviously it may be of any suitable construction or arrangement. The bindingposts 7 and 8 are also secured to the cap 2, preferably one on each side of the attaching device 6. To one of these is connected the incoming line-wire 9, and, as usually arranged, the currentpasses from this through resistance-coils 10, thence through the solenoid 11, and thence (by Way of the frame part 1) to the upper carbon 12, thence to the lower carbon 13 and its frame, thence by way of the wire 15 to the other binding-post and out over the outgoing line-wire 16. I have thus briefly described the general structure of the lamp and the ordinary course of the current before proceeding to describe the details.

The solenoid 11 difiers from ordinary solenoids in being provided with an external shell 17, as well as an ordinary core 18, by means of which it is given increased power. Above the solenoid is a branched lever 19, mounted by means of a fulcrum-pin f on a suitable bearing or projection on the central framepiece 1. One end of this lever is connected to the core and shell 17 18 of the solenoid by means of a link 20, and the other end is connected toa dash-pot 21 by means of a link 22. The lamp is adjusted for different voltages by shifting the fulcrum-pinf from one to another of two or more holes provided therefor in the branched lever 19. The link 22 is also a part of the lifting-clutch "mechanism, as substantially a continuation thereof, "23, --extends inside or alongside of the dash-pot to the clutch 24, by which the upper carbon 12 is from time to time lifted in the operation of the lamp. The advantage ofthis'arrangement is that there is no other and uncovered opening needed inthe frame creasing for the" passage of the clutch-lifting rod, and this opening being well covered by the dash-'potii the resultis that the air is more perfectly exeluded from "the chamber containing the arc than would otherwise be-the case. If itisi preferred to run the rod 23 down outside the, dash-pot, the opening in the frame should be in the form of a stuffing-box. The clutch itself works in an ordinaryand well-known manner, and its operation is well understood by those skilled in the art.

In providing for a perfect sliding contact by which'the electrical connection between the upper carbon and the frameis maintained I'place within the hollow main frame-piece 1 a tube 25, having a smooth interior surface and preferably formed of brass, which is permanently and amply secured therein both mechanically and electrically. Upon the'u'pper end of the upper carbon 12 -I place "a clamping cap composed, essentially, of a split-sided tube '26, the fingers of which embrace the carbon, the remainder of said tube being filled with a solid body of metal and surrounding which are several spring-fingers 27, which spread out and bear constantly and equally upon the inner surface of the tube 25.

As shown, the upper portion of the central main frame-piece 1 is preferably substantially cylindrical in form and provided with suitable projections upon which to mount the adjacent parts. The lower portion .is preferably enlarged considerably in one direction in order to provide a chamber of suflicient size to contain the clutch mechanism comfortably. The lower end of this main frame portion is substantially a disk 28, against which the top of the inner globe 29 rests and which forms the upper wall of the chamber of jWhlCh said globe forms the remainder.

. Theiglobe and the disk being nicely fitted together, as shown in the-drawings, and there being no other perforation leading into the inclosure except that through which the rod operating-the clutch passes, (which is itself inclosed within the dash-pot,) it will be seen that when the parts are properly fitted together little if any air can enter said chamber.

The globe 29 is held against theplate 28'by means of latches 30, pivoted to verticallymovable rods 31, which are normally held upwardly by meansof springs 32. As best shown in Fig. 4, these latches are formed to engage with lugs l on the main frame part 1 when they are in position for holding the globe, but are enabled to escape from said lugs when pulled downwardly, so that the springs 32 are compressed and in that' posi'ti'on' can be 'swung outwardly, as indicated by the dotted lines, so that the globe 29 canbe removed. An alternative construction of these latches is shown in Fig. 8, in which the vertical move.- ment-of-the'devvice is't'he same, but in which a projection on-the side of the latch escapes from aslot when the latc'hispdlled downwardly, so that it may be partially revolved in its bearings instead of being swung outwardly ona pivot. same, as the engaging jaw is by the movement -described-removed from contact with the rib r at the upper end of the globe, which rib, as will'be'rea'di'ly s'een,isthe means for engagement with either form of latch, Said rib also provides a means 'vrh'ereby 'a circumferential cavity orch-amb'er-is formed around the upper end of the globe, which experiment has shown'tobedesirab-le i-n lamps of this character, as it has a tendency'to arrest'and'hold any small amount of airwhich may accidentally enter the globe and prevent'it fromdescendiug to the point where the carbons'are in contact,-and thus-exerci'singits effect upon the combustion there going on.

- Having thus fullydescri-bed mysaid invention, what I claim as new, and desire to secu re by Letters Patent, is-

1. The combination,in an electric-arc lamp, of a central'tubula-r frame .p'art upon which the-mechanism of the 'lam-p'i'smounted, a-c'a'p portion secured to the upper end of said tubular frame'part, and hinged portions adapted to form sides and 'with'the said cap to inclose and-'cover the lamp mechanism, substantially as shown and described.

2. Thecombination, in an electric-arc lamp, of acentralframe portion, ac'ap'portion thereon, and hinged portions forming sides to the lower casing, said'hingedside portions having flanges at the lower end constituting a globe-holder and providedwith a suitable catch whereby they "are held together when closed, substantially as-and for the purposes set forth.

The result in each case is the 3. The co mbin atio n, in an electric arc la'mp,

of the hollow=main central frame portion' extending to the top of the lamp, the cap and side portionsof the casing attached thereto supported on the top of said hollow central frame portion, a guide-tube-for the carbonholder mounted within said hollow frame portion and supported from its top, a clutch mechanism within a chamber at the lower end of said hollow frameportion, a globe fitted against the lower end of "the central frame, means whereby said globe isheld in place, an electric controlling device, a dash-pot, a lever connected at one end 'to' the moving portion of the electric controlling device and at the other end to said dash-pot, a clutch-rod running from the dash-pot mechanism down through the shell of the frame-to within the chamber and attached at its lower end to the clutch mechanism, the opening in said shell being arranged to exclude the passage of air, substantially as and for the purposes set forth.

4:. The combination in an electric-arc lamp, of the frame, the globe 29 seated closely onto said frame, and provided with a circumferential rib, and latches pivoted to vertical spring-mounted rods carried on the frame and adapted to engage with said rib, substantially as set forth.

5. In a device using a glass globe, the combination of a supporting-body, a lug on said body drilled to receive a rod, a rod adapted to move longitudinally in said hole and engaging with the globe so as to support the same, a spring tending to lift said rod and a handle adapted to revolve the rod around its axis and throw it out of engagement with the globe, substantially as set forth.

6. In an arc-lamp the combination with the frame thereof, of a current-contact, carbonguide and cut-out, composed of a flat circular part, a cylindrical solid piece, a cylindrical tube fitting and surrounding said solid piece and extending beyond it, one or more slots in said tube extending beyond the end of the solid piece and one or more spring-fingers supported from the end carrying the circular piece and adapted so as to be free to spring laterally outward, substantially as described.

7. In a globe-carrying device the combination with a flanged globe, of a main supporting-body, one or more lugs supported by said body and projecting under the flange of the globe, a pivoted catch with the part arranged to project under and support the flange of the globe, and adapted to revolve upward around the fulcrum until it clears the edge of the globe, substantially as described.

In Witness whereof I have hereunto set my hand and seal, at Indianapolis, Indiana, this 7th day of December, A. D. 1899.

WILLIAM H. NORTHALL. [n s] Witnesses:

CHESTER BRADFORD, JAMES A. WALSH. 

